Abstract: A graph converter converts functionally descriptive information expressing a combination circuit into a graph expression having only NOR and inversion circuits. A multiple input NOR converter detects from the above graph expression a circuit element having a NOR circuit and an inversion circuit alternately connected in series and converts the circuit element to a graph expression where a multiple input NOR circuit replaces the circuit element. A cell mapper detects from the above graph expression a circuit element having NOR circuits connected together in series, maps the circuit element to gate cells with or without a composite cell, and outputs the mapping result with the least number of gates as the mapping output for the circuit element. A circuit element having a NOR circuit and an inversion circuit alternately connected in series is substituted by a unique multiple input NOR circuit.

Abstract: A rule base processing system for processing rules with an inference engine is provided with a control block and a number of knowledge source blocks containing the rules. The control block contains a knowledge source list of the knowledge source blocks and a function name through which the control block may be called as a subprogram. The knowledge source blocks contain priority sequence tables in which the sequence of execution of the rules is arranged and can be externally controlled. Each rule in the knowledge source contains a number of detailed rules from which an optimum rule is selected.